So I've been having problems with my H115i since getting it. I had an Asus ROG STRIX Z270F, but it started flaking out very quickly. I'm now running an MSI Z270 SLI PLUS.

On install, there was some play between the backplate and screws. After installing the cooler, there is none. I tried installing some small silicone washers on the Asus, it made no difference. The install is with Arctic Silver Arctic Alumina, following the install directions from Arctic Silver - 1mm thin line down the center of the spreader. I also tried the old-school application method, spreading a very thin layer across the spreader. No better.

On idle, temps sit at around 30c. Loaded with x264 stress test, they immediately hit 70c+. The coolant temperature never goes over 33c. This is with the pump on performance, and putting the fans at max doesn't make a difference.

It's not likely either. Take a look at your peak Vcore values -- you are hitting 1.35v. That's enough to clock willing processors to 5.0 GHz. Kaby, like Skylake before it, is overly flexible in the default configuration where the goal is maximum stability at the intended settings, not thermal efficiency under synthetic testing. It ramps the voltage up substantially during those moments. Part of the solution is to set your own specific adaptive voltage, even if you intend to run the standard frequency. Also, most of the boards have some way or another to limit the load line. I don't know the MSI BIOS on that board, but I think you will be able to find it with a some more targeted searching.

Event though you have dropped the Asus, their OC guide provides some understanding of the limitations.

The Tom's Review has some thorough power numbers to further illustrate the issue, but he telling quote is:

"Dissipating almost 140W isn't really a challenge for our water cooling solution. It’s able to deal with an Intel Core i7-6950X overclocked to 4 GHz, which generates a lot more heat than this. The problems lie elsewhere. First, there’s the CPU package's smaller surface area. Second, there’s the thermal paste, which might have made Intel's accounting department happy, but causes overclockers nothing but worry."

This CPU is never going to be a benchmark fiends dream, but that does not mean it is a poor performer for normal use. Use it for your normal programs and see what comes back, but also keep in mind there is difference between CPU spikes and a higher average core temperature. No cooler can prevent those CPU spikes you get when launching programs or at a certain section of a game. That is down to CPU, voltage, and instruction.

You're correct, and I feel like an idiot. Didn't realize it was going adaptive on voltage right out of the box, and I didn't look. I just cranked ratio to 49, locked voltage at 1.26 and now it sits at about 75c. <facepalm> Coolant is sitting at 27ish. Should that be going up after an extended time of the CPU sitting at 75c?

Thanks for the help, should have taken more time looking at the new motherboard. I don't want to delid, but really feel like I should be considering it to get the most out of the CPU and H115i...

You're correct, and I feel like an idiot. Didn't realize it was going adaptive on voltage right out of the box, and I didn't look. I just cranked ratio to 49, locked voltage at 1.26 and now it sits at about 75c. <facepalm> Coolant is sitting at 27ish. Should that be going up after an extended time of the CPU sitting at 75c?

Thanks for the help, should have taken more time looking at the new motherboard.

No, this is a really common question and most people are surprised when they run the "old standard tests" on the new CPUs. It is big change for anyone coming from Sandy Bridge era or thereabouts.

I know what you mean. I have been eyeing this CPU and was considering dismantling my current set-up for one of the very nice looking Z270 boards. But part of that analysis was that I would need to delid to make myself happy. Hard to swallow right at the start. On the other hand, this may mean you can run 5.0/1.35v and stay under 80.

No, this is a really common question and most people are surprised when they run the "old standard tests" on the new CPUs. It is big change for anyone coming from Sandy Bridge era or thereabouts.

I know what you mean. I have been eyeing this CPU and was considering dismantling my current set-up for one of the very nice looking Z270 boards. But part of that analysis was that I would need to delid to make myself happy. Hard to swallow right at the start. On the other hand, this may mean you can run 5.0/1.35v and stay under 80.

I ended up ordering the Rockit88 tool and some Liquid Ultra. Will be my first time delidding.